Re: Well you can but... - Saab NG900 & OG9-3 Bulletin Board - Saabnet.com
The banner above is an advertisment - if it asks you to download software, please ignore.
Site News -
7/1: Members: Log In to See Fewer Ads! |
5/28: SAAB Evolutions/TSN T-Shirts $14
[General |
Members |
C900 |
9000 |
NG900 & OG93 |
93 |
95 |
NG95 |
99 |
Sonett |
Vintage Models |
Clubs |
Other Cars |
FAQs |
Gifts |
Member Photo Galleries |
Member Directory |
Classifieds |
Manuals |
*Buddy Registry |
*Mileage Registry |
Polls |
What's New |
Raffle |
Photo of the Month |
Sponsors]
[Main NG900 & OG93 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Re: Well you can but...
Posted by Dean (more from Dean) on Thu, 17 Jul 2003 06:46:46
In Reply to: Well you can but..., Schu, Thu, 17 Jul 2003 04:48:43
Members do not see ads below this line. - Help Keep This Site Online - Signup
So in summary:
You are not letting the BPC have access to any pressure to start opening the wastegate until the pressure gets up to a point where the MBC starts to flow. The MBC will also reduce the pressure that the BPC valve has to work with, but it will adapt. Why does this help? The BPC is an electrically modulated bleeder valve and all bleeder valves have the characteristic of applying a varying but proportional pressure to the WGA. So while a bleeder valve will provide a good steady state boost control, it has problems during the spoolup transient condtions. The WGA will be slowly opening as the pressure increases. So mid way thru the transtion to boost the WGA will be opening and this will reduce the exhaust flow thru the turbine. So the whole process takes a long time. This is not turbo lag, but it is boost delay created by the controller. With the T5's when folks install a MBC they get the turbo spooling up as fast as it can and that is very much faster than stock. In that case they experience turbo lag which is not much compared to the controller's boost delay. It can be an explosive increase in torque where all kinds of new throttle techniques need to be learned. - the end of linear throttle response!
One can also install the MBC infront of the PBC with the MBC's bleed orifice blocked off. The BPC will get full turbo pressure once the MBC starts to flow. If a MBC is installed between the BPC and the WGA the bleed orifice must be left open or the WGA would not want to close once open. So there are three combo's. Which is best? I do not know and there might not be much difference between them.
posted by 207.43.195...
Posts in this Thread:
Members do not see ads below this line. - Help Keep This Site Online - Signup
Post a Followup
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
StateOfNine.com
![](/tsn/xyz/stateofninebutton.gif) |
SaabClub.com
![](/tsn/xyz/scnabutton.gif) |
Jak Stoll Performance
![](/tsn/xyz/jakstollbutton.gif) |
M Car Covers
![](/tsn/xyz/mcarcoversbutton.gif) |
Ad Available
![](/tsn/xyz/buttonavailable.gif) |
![](/tsn/images/tsnmap.gif)
Random Saabnet.com Member Gallery Photos (Click Image)
This is a moderated bulletin board - Posting is a privilege, not a right.
Unsolicited commercial postings are not allowed (no spam). Please, no For Sale or Wanted postings, SERIOUSLY.
Classifieds are to be listed in The Saab Network Classifieds pages.
This is a problem solving forum for over 250,000 Saab owners, so expect to see
problems discussed here even though our cars are generally very reliable. This is not an anything goes
type of forum. Saabnet.com has been a moderated forum since 1988. For usage guidelines, see the
Saabnet.com Mission and Purpose Page. Please remember that you are
not anonymous. Site Contact | Site Donations | Other Sites by SP -
Poverty2Prosperity.org | Run Club Menlo Park | ScreenBot
Site Members do not see red text instructions, bottom of the page anchor ads, or box ads.
Click here to see all
the Site Membership Benefits!